1. Field of the Invention
The synthetic production of a wide variety of drugs and naturally occurring products is dependent upon the introduction of an oxygen functionality at a particular site. Frequently, the oxygen functionality may be associated with a second functionality in the vicinal position. For many compounds of interest, one or both of these sites may be chiral. The epoxide functionality is a particularly attractive functionality for providing the two substituents. Furthermore, where the epoxide can be provided as a particular enantiomer or diastereomer, by appropriate selection of reagents and conditions, one can provide for the correct stereoisomers at the two positions. There is, therefore, substantial interest in ways to prepare epoxides in high yield providing for asymmetric formation of the epoxide.
2. Description of the Prior Art
U.S. Pat. No. 4,471,130 describes asymmetric epoxidation of ethylenic alcohols employing, for the most part, stoichiometric amounts of metal alkoxide catalyst. Numerous other articles have been published employing the process described in the above-cited U.S. patent, using a wide variety of olefinic alcohols for epoxide formation, substantially following the stoichiometric conditions described in the cited patent. The disclosure of U.S. Pat. No. 4,471,130 is incorporated herein by reference in its entirety.